Methylene-hippuric acid and process of making same.



UNITED STATES Patented November 10, 1903.

PATENT OFFICE.

ARTHUR N IOOLAIER AND PAUL HUNSALZ, OF BERLIN, GERMANY, ASSIGNORS 7 TO CHEMISOHE FABRIK AUF ACTIEN, VORM. E. SCHERING, OF BERLIN,

GERMANY.

METHYLENE-HIPPURIC ACID AND PROCESS OF MAKING SAME.

: SPECIFICATION forming part of Letters Patent N 0. 743,986, dated November 10, 1903.

Application filed June 11, 1903. Serial No. 161,025- (Specimens-l To all whom it may concern.-

Be it known that we, ARTHUR NIOOLAIER, doctor of medicine,and PAUL HUNSALZ,clien1- ist, doctor of philosophy, residing at Berlin,

5 Germany, have'invented a new and useful Improvement in Processes of Making Methylene-Hippuric Acid, of which the following is a specification.

According to our invention methylene-hip- IO puric acid which is of use in therapeutics is manufactured by causing means of methylenation to react upon hippurio acid-for example, by dissolving hippuricj acid in sulfuric acid and adding polymeric formaldehyde in excess or less advantageously by heating hippuric acid with a solution of formaldehyde'with or withoutthe use of means for condensation, &c.

In the reaction of formaldehyde upon hippuric acid the methylene radical attaches itself both to the imido group and to the carboxylic group. Methylene-hippuric acid may,

for example, be manufactured as follows; One

hundred grams of hippuric acid is shaken v2 5 with seventy-five grams of paraformaldehyde and five hundred grams of concentrated sulfuric acid until dissolved and is allowed to stand at the ordinary temperature for four days. The mixture is then poured into ice 0 and the precipitate filtered off. This precipitate is then thoroughly mixed with a cold solution of sodium acetate in excess and filtered after standing for half an hour. The hippuric acid is thereby dissolved, while the I product of the reaction remains behind.

Methylene-hippuric acid is a white crystalline powder, being difticultly soluble in Water, more easily soluble in hot benzol and petroleum ether. The compound crystallizes out of hot acetic ether, in which it is very easily soluble in prismatic crystals, which melt at about 151 centi grade. As this acid also only slowly dissolves in soda solution and is apparently decomposed, an ether-like derivative of hippuric acid is probably formed of the following constitution:

ARTHUR NICOLAIER. PAUL HUNSALZ.

Witnesses W OLDEMAR HAUPT, HENRY HASPER. 

